Autosomal <i>P[ovo</i> <i>D1</i> <i>]</i> dominant female-sterile insertions in <i>Drosophila</i> and their use in generating germ-line chimeras

TLDR

The dominant female‑sterile (DFS) technique in Drosophila, which blocks egg laying without affecting viability, is a powerful tool for determining tissue specificity of recessive female‑sterile mutations and analyzing maternal effects, but has been limited to the X‑chromosome because only the X‑linked ovoD1 mutation fulfills the required criteria. The authors aim to extend the DFS technique to autosomes by cloning ovoD1 into a P‑element vector, generating fully expressed P[ovoD1] insertions on each autosomal arm, and demonstrating their use for creating germ‑line chimeras. They cloned the ovoD1 mutation into a P‑element vector, inserted it into each autosomal arm, and expressed it to produce dominant female‑sterile mutations that block egg laying while preserving viability. They demonstrate that the Gap1 gene, a Drosophila homolog of mammalian GTPase‑activating protein, is required in somatic follicle cells for embryonic dorsoventral polarity determination.

Abstract

The 'dominant female-sterile' technique used to generate germ-line mosaics in Drosophila is a powerful tool to determine the tissue specificity (germ line versus somatic) of recessive female-sterile mutations as well as to analyze the maternal effect of recessive zygotic lethal mutations. This technique requires the availability of germ-line-dependent, dominant female-sterile (DFS) mutations that block egg laying but do not affect viability. To date only one X-linked mutation, ovoD1 has been isolated that completely fulfills these criteria. Thus the 'DFS technique' has been largely limited to the X-chromosome. To extend this technique to the autosomes, we have cloned the ovoD1 mutation into a P-element vector and recovered fully expressed P[ovoD1] insertions on each autosomal arm. We describe the generation of these P[ovoD1] strains as well as demonstrate their use in generating germ-line chimeras. Specifically, we show that the Gap1 gene, which encodes a Drosophila homologue of mammalian GTPase-activating protein, is required in somatic follicle cells for embryonic dorsoventral polarity determination.